<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*id选择器*/
        #p1{color: red}
        /*类选择器*/
        .c1{color: blue}
        /*分组选择器*/
        h3,#p1,.c1{background-color: yellow}
        /*属性选择器*/
        input[type='text']{background-color: red}
        input[type='password']{color: green}
        /*任意元素选择器*/
        *{
            /*边框:粗细  样式   颜色*/
            border: 1px solid red;
        }
    </style>
</head>
<body><!---->
    <input type="text">
    <input type="password">
    <h3>我是h3</h3>
    <p id="p1">苹果</p><p class="c1">香蕉</p><p>橘子</p>
    <div>冰箱</div>
    <div class="c1">洗衣机</div>
    <div>电视</div>
</body>
</html>